Spinal disc or partial spinal disc replacement is a common procedure in Europe with thousands having been performed already and is now commencing in the United States. Examples of such replacement discs are ProDisc (Spine Solutions, Inc.) and SB Charite III (Link Spine Group, Inc.)
By replacing a disc and not merely fusing vertebrae, which is the common alternative practice to disc replacement, the mobility of the patient's adjacent discs may be preserved and thus may delay the onset of arthritic changes to adjacent vertebrae.
A typical disc replacement unit is approximately 30 millimeters in diameter. This relatively large cross-section usually necessitates a mostly anterior retroperitoneal (from the front of the abdomen but staying outside the intestinal sac) approach to the spine which may be risky. The risks of general anesthesia are coupled with risks of vascular injury and retrograde ejaculation in males.
Although many prosthetic disc devices are described in the literature, there is still a need for improvement in ease of manufacture and performance and of the preparation of the space for the insertion of the prosthesis.